Two Powers

Historians commonly designate the High Middle Ages as the era of the "papal monarchy," when the popes of Rome vied with secular rulers for spiritual and temporal supremacy. Indeed, in many ways the story of the papal monarchy encapsulates that of medieval Europe as often remembered: a time before the modern age, when religious authorities openly clashed with emperors, kings, and princes for political mastery of their world, claiming sovereignty over Christendom, the universal community of Christian kingdoms, churches, and peoples. At no point was this conflict more widespread and dramatic…